The feeling at the Comic-Con International panel was that “Once Upon a Time” didn’t end on a cliffhanger so much as on a note of extreme anticipation: “Frozen’s” Elsa is coming. But the creators made everyone wait until the end because love was in the air.

Before the panel was introduced, the crowd got to see a trailer for the forthcoming fourth season of the show, which was really a compilation of images and scenes from all the past seasons, highlighted by the introduction of Elsa from “Frozen.” We can call it season 4.5 since “Once” has recently been splitting up seasons into two distinct story lines, with last season spotlighting the villains Peter Pan and the Wicked Witch of the West.

Creators Edward Kitsis and Adam Horowitz, alongside actors Jennifer Morrison, Josh Dallas, Lana Parrilla, Emily De Ravin, Jared Gilmore, Colin O’Donoghue and Robert Carlyle, all came on stage to rapturous applause, spurred on by moderator and self-proclaimed fangirl Yvette Nicole Brown as moderator. Brown was actually the voice of Ursula from “The Little Mermaid” in her appearance on “Once Upon a Time.”

Brown started off what would be a theme of the panel, asking the creators what the difference is between true love and soulmates. Kitsis and Horowitz struggled with it for a bit, but basically said that both can be “in flux,” though the idea is that your soulmate is that one person you’re destined to be with, and true love is almost magical.

After a series of questions on the relationship between Ravin’s Belle and Carlyle’s Rumpelstiltskin — with Carlyle saying he believe Rumpel truly loves Belle and Ravin speculating that Belle may be a little too trusting — Horowitz and Kitsis brought along a funny video introducing the audience to the writers’ room for the show. During what they called a mini-camp, the writers realized that they seemed to have exhausted their roster of villains. It took a pizza delivery guy — after Horowitz and Kitsis tried to call their fellow “Lost” creator Carlton Cuse for advice — to come up with the idea to spotlight “Frozen.”

More questions from Brown centered on the relationships between Carlyle’s Rumpel and Gilmore’s Henry, Morrison’s Swan and O’Donoghue’s Hook, and John Dallas’ real-life relationship with costar Ginnifer Goodwin, who gave birth on both the show and in real-life last season. She was back in Vancouver on set Saturday, but had a video message for the fans. Michael Socha, who plays the Knave of Hearts, made an appearance on the video, promptly getting knocked out by Goodwin, who joked that motherhood had not caused her to have mood swings or depression.

The audience, many in costumed iterations of the show’s characters, asked some of the panelists specific acting questions. Parrilla was asked about playing a “good” Regina versus her evil persona. (“I think it’s quite refreshing. She’s such a colorful, complex woman.”) Carlyle was asked about being in scenes where his on-screen son dies. (“It’s very emotional, but they are the scenes that actors love.”) And Morrison was asked by Brown about the danger she may be in since she helped to possibly break Regina’s heart, (“It’s an impossible situation, but I think Emma’s going to be determined to keep [Regina] in a good place.”)

Finally, “Frozen.” Kitsis and Horowitz introduced a clip from the upcoming season spotlighting the sister characters Anna (Elizabeth Lail) and Elsa (Georgina Haig) from “Frozen” as they visit what looks to be their parents’ graves. Elsa tells Anna that she has a surprise for her wedding. It was probably the moment that most of the audience was waiting for, and though it was a more quiet, reflective clip, it served to satiate the assembled with our first real view of the duo interacting onscreen.

That wasn’t the only look at next season. As the panel let out, one more scene was shown to the faithful. Evil Queen and Mayor Regina goes back to a restricted area of what looks to be Storybrooke’s hospital — possibly the same area where she held Belle a few seasons ago. She opens a door and tells an imprisoned, disheveled Magic Mirror, played by Giancarlo Esposito, that she needs his help.